Carlton coach Brett Ratten admits his side's AFL season has stalled on the back of producing what he says is their worst half of football during his time in charge.

Despite not having made finals since 2001, the Blues entered this season carrying enormous expectations, further enhanced when they thrashed Richmond by 83 points in a much-hyped opening game.

But three losses in the past four rounds - culminating in Saturday's 44-point thrashing by Adelaide at AAMI Stadium - have sent them tumbling from the top eight for the first time this year.

Compounding the pain, the club confirmed on Tuesday that versatile key-position player Jarrad Waite will need a full knee reconstruction and miss the rest of the season.

Ratten said he did not believe the Blues' pre-season and opening round form had created unrealistically high expectations.

But he said more disturbing than their fall into the bottom half of the ladder and 4-5 record was the football they dished up in the first half on Saturday, when they failed to kick a goal.

"As a football club where we've sat with our history, we want to play finals football, that's always been our aim," Ratten said.

"If you go into any season, we won 10 games last year so we think we can improve on that.

"We've probably stalled a little bit in our progress at the moment.

"That was the worst half of footy in my time as coach that we've had at the club."

Ratten has coached the club to 14 wins and 23 losses from 37 matches since taking over from Denis Pagan late in 2007.

He said in many defeats there were positives to draw on, but not this one.

"You look at the Hawthorn game (in round six), that was a game we lost but you walk away thinking there was a lot to like about that performance and that intensity," Ratten said.

"Then you have a look at this week and walk away with a bit of bitterness in your mouth, you think that's not how we play."

Ratten said he needed to take responsibility for Carlton's overly defensive set-up against the Crows.

On numerous occasions, they had every player in their defensive half, with even star forward Brendan Fevola spending time in defence.

Ratten said he had wanted his players to provide more defensive support than in previous rounds, but not to that extent.

"You look at the front 50 and no-one's up there and you're thinking `We're never going to score'," he said.

"... I'll take full responsibility, that's the team that runs out and if that's how it's been taken I need to change that."

Not helping the Blues' cause is Fevola's form struggles, with just two goals in the past three rounds.

Speculation persists that the spearhead, who booted 99 goals last season, is still being hampered by recent leg muscle and heel injuries, but Ratten was adamant that was untrue.

"There's no physical reason, he's fine, he's fit," Ratten said.

He noted Fevola kicked 1.5 against the Crows and said had he kicked straight his form would not be considered an issue.

The Blues face a must-win match against West Coast at Etihad Stadium on Friday night.

"We need to win and there'll be a bit of pressure on the boys but with that a bit of excitement, who's going to turn around that first half of last week into a fantastic start this week?" Ratten said.

Brought to you by AAP © 2024 AAP